Link



y 28, 1931- A. J. LOEPSINGER 1,816,017

LINK

Filed Jan. 2, 1929 Inventor (218% J. Loepfiinger a tfo 7 2152 lessresponsive to .heatchanges. 'In extreme Patented July 28, 1931 TED sr-Ares PATENT "OFFICE Arsenicugiioersrnenn, or rnovrnnncn, nnonn rsLn-nn-iassmivon :roenmmar. "rmsnxrnveursnsn 'COMYAN'Y, or rRovIDENcE,iiironn'rsraivn, econ-rennrrrou or DELAWARE I 1 7 Application filedlfanuary 2,

This invention relates to improvements, .in

links.","More'especiallyit has to do withthermally responsive linkswhich upon rise of temperature to a predetermined degreegglve is way;and: thereby free whatever has been held thertendency of suchtmaterialto yield grad ually at nnormaltemperatures it has become customary tointerlock theseparable parts of thei'link soathatf these partsthemselves will carry the major portion. of the load whilethe fusible(material is =-maintaining .this interlocked relation. By thus lesseningthe amount .of' strain onv the-material the .trouble from .cold flowislargely avoided but the arrangement; is not entirely satisfactorybecause the fusible. material is usually more or less insulated as itwere by the;interlocked parts; and does not respond asquickly tochanges: of temperature.

-Moreover' all fusible materialis subject to corrosion. In some casesthis eats-awaythe fusible material and permits a premature rupture ofthe'linkwith possible damaging results if the link has been holding afire eX-- tinguishing: agent in restraint. 'Far. greater diflicultiesare encountered, 1 however, in; the cases where the eifectofthecorrosionisuto change the/molecular structure of the fusible metal as forexample. where it forms a: sulphideof the metal. :Thisactionisnot-apparent-because 1 the 1 external appearance of the material isunchanged, but its effects are exceedingly dangerous because theresulting material has greater holdingpower and is cases thematerial in'fact' becomes non-fusible. Accordingly, it is not uncommon to findfusible links so corroded as to be entirely inoperative in respect tothe functions they are 1 expected to perform. This is obviouslyadangerous possibility and one likely to be 11nnoticed because, aspreviously stated, the effects of the corrosion can not be seen and theactual condition of the fusible material can s not be determined byvisual inspection.

at; relatively high temperatures. Because of LINK 1929. .Serial 1N0.329,817.

peratures, which will not require supervision or: maintenance, whichwill respond unfailinglywhen needed, and which has as its yielding'element one which-is capable of bearing the'full forceexerted upon: thelink. .It isto the provision of-such. a link that the present invention.is directed.

RA principal objectofth-is invention isto provide a simple? linkcomprising only separable members which-are engaged by the ties andanelement holding saidmembersagainst separation. It is a. feature of theinvention that-this element bears all the loadimposed on theilink, isnoncorrodible, andbecomes entirely destroyed when heated to. apredeterminedtemperature, thus completely severing allconnectionbetweenthe ties. As herein illustrated, the thermally responsive elementis .aifrangible vessel preferably -made of quartzan'd containing acharge of expansible fluid whichupon being heated to predetermineddegree completely destroys. thevessel. The latter may bemade' fromtubing with its end portions formed, generally in "spherical shape,:eachend beingjoined to the main body: portion of the'vessel by. a neckportion of somewhat smaller dimension. Theiend members of the linkengage onlythe spherical ends of the frangible vessel so that the forcetransmitted by them is entirely carried by the vessel. "Upon the ruptureor destruction of thevessel the li'nk ends are instantly and completelyset free "with no chance of their becoming entangled or interlocked withone another.

ItIis intended thatthe; patent shall cover by suitable expression inthe-appendedclaims whatever features of patentable novelty exist intheinvention disclosed.

In the accompanying drawings,

Figure l is an elevation partly in Section of a thermally responsivelink constructed in accordance with the principles of the invention.

, Figure 2 is a. similar view of thesame link viewed as from the leftofFigure 1;

Figures 3 and 4 are similar views showing a modified form of link ends;and

Figure 5 is a view showing the linkend of Figures 3 and 4 as it may bestamped from sheet stock.

Referring particularly to the drawings, the I link of Figures 1 and 2has end members A formed with a flat portion A1 and a hollow cylindricalportion A2 in alignment with the flat portion. Each end portion hasahole edged with a'grommet B through which ties may be secured to thelink. A spherical or ball-shaped end C1 of a frangible vessel 0 isinserted within the hollow ofthe cylindrical portion of each end member,the rim A3 of the cylinder being then turnedor spun inward to fitsomewhat loosely about the neck C2 of the vessel. T'husthe separable endmembers of the link are joined to the vessel. The latter is preferablymade of quartz initially formed as a tube and then fused and drawn intoa vessel of the shape disclosed, with its ends generally spherical andjoined to the body portion C3-by'the contracted neck portions C2. Beforebeing entirely sealed the vessel is charged with a fluid that expandsupon being heated. The relation of the expansive force of this fluid tothe temperature is such that'the degree at which the vessel will fail towithstand itsinternal pressure can be predetermined with considerableaccuracy. Consequently a link employing the frangible vessel as itsthermally responsive elementcan be depended upon to withstand withoutchange the eflects of all normal temperature and to-be completelydestroyed when exposed to a temperature at which the expansive force ofthe'fiuid overcomes the strength of the quartz shell. The latter, ofcourse, is noncorrosive and by selecting suitable metal for the linkends the danger from corrosion is substantially eliminated.

The link of Figures 3 and 4 has end members D which can be stamped fromsheet stock in the form of a strip with a hole D1 at one end and slot D2extendingfrom a similar hole D3 at the other end slightly more than halfthe length of the strip. The hole D3 is larger than the diameter of theballshaped end C1 of the frangible vessel so that the latter can beinserted therethrough and its neck portion C2 slipped along theslot D2.The strip is then bent around to form a ring D4 with portions D5 off-settherefrom which are 7 clamped together by the grommet B. Thus theball-end of the vessel is held within the ring of the end member.

Ties (not shown) are attached "to the sepselves in alignment'althoughthere maybe an angular divergance between the planes of the grommets B.The term tie as used in the claims is not to be limited to a flexibleband or fastening, but is to be taken as representative of anyforce-exerting agency capable of being attached to the end members. Iclaim as my invention: '1. A thermally responsive link comprising,

in combination, separable means adapted to be connected to ties and afrangible vessel holding said separable means from separating andcontaining an eXpansib-le fluid adapted upon rise of temperature to apredeterrmined degree to destroy said vessel and thereby free saidseparable means; the said means being connected to the ends of saidfrangible vessel to permit limited relative movement between them. 1

2. A thermally responsive link comprising, in combination, a frangiblevessel containing a chargeof expansible fluid-adapted upon beingheatedto a predetermined degree to destroy said vessel; and separable membersadapted to be connected to ties and engaging said vessel near its endswith said engagement holding said members from separating until thedestruction of the frangible vessel. r

' 3. A thermally responsive link comprising,

in combination, a frangible vessel containing a charge of expansibleflllld adapted upon being heated to a predetermined degree to destroysaid vessel; and separable members adapted to be connected to ties,eachmember having a ring-shaped portion engaging the surface of saidfrangiblevessel 1n a manner to permit limited relative movement betweenthem while preventing separation of said members vessel.-

Signed at Providence, Rhode Island, this 28th day of December, 1928.

prior to the destructionof the said freedom for limited relativemovement between them,

. 12o ALBERT 4 J. LOEPSING ER.

